﻿using System.Windows;
using AzureTracer;
using AzureTracer.Model;
using AzureTracer.Services;
using AzureTracerScheduledTask.Common;
using Microsoft.Phone.Scheduler;

namespace AzureTracerScheduledTask
{
    public class ScheduledAgent : ScheduledTaskAgent
    {
        private static volatile bool _classInitialized;

        /// <remarks>
        /// ScheduledAgent constructor, initializes the UnhandledException handler
        /// </remarks>
        public ScheduledAgent()
        {
            if (!_classInitialized)
            {
                _classInitialized = true;
                // Subscribe to the managed exception handler
                Deployment.Current.Dispatcher.BeginInvoke(delegate
                {
                    Application.Current.UnhandledException += ScheduledAgent_UnhandledException;
                });
            }
        }

        /// Code to execute on Unhandled Exceptions
        private void ScheduledAgent_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // An unhandled exception has occurred; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
        }

        /// <summary>
        /// Agent that runs a scheduled task
        /// </summary>
        /// <param name="task">
        /// The invoked task
        /// </param>
        /// <remarks>
        /// This method is called when a periodic or resource intensive task is invoked
        /// </remarks>
        protected override void OnInvoke(ScheduledTask task)
        {
            AppSettings appSettings = new AppSettings();
            DataStateManager.LoadGlobalSettings(appSettings);

            if (!appSettings.ReadyToSync())
            {
                NotifyComplete();
                return;
            }

            AzureLogService logService = new AzureLogService(appSettings);
            DataStateManager.LoadGlobalDataFromStorage(logService);

            logService.LoadData((count, exception) =>
                {
                    if (exception == null)
                    {
                        appSettings.BackgroundItemsCount += count;

                        DataStateManager.SaveGlobalDataToStorage(logService);
                        DataStateManager.SaveGlobalSettings(appSettings);

                        TileHelper.UpdateTileCount(appSettings.BackgroundItemsCount);

                        NotifyComplete();
                    }
                    else
                    {
                        Abort();
                    }
                });
        }
    }
}